The reciprocal interaction between sleep and pain has been reported by numerous studies. Patients with acute or chronic pain often complain of difficulty falling asleep, frequent awakenings, shorter sleep duration, unrefreshing sleep, and poor sleep quality in general. According to the majority of the experimental human studies, sleep deprivation may produce hyperalgesic changes. The selective disruption of slow wave sleep has shown this effect more consistently, while results after selective REM sleep deprivation remain unclear. Patients with chronic pain have a marked alteration of sleep structure and continuity, such as frequent sleep-stage shifts, increased nocturnal awakenings, decreased slow wave sleep (SWS), decreased rapid eye movement (REM) sleep, and alpha-delta sleep. Many analgesic medications can alter sleep architecture in a manner similar to the effects of acute and chronic pain, suppressing SWS and REM sleep.
Chronic Pain ; Humans ; Sleep Deprivation ; Sleep, REM

OBJECTIVES: Obstructive sleep apnea syndrome (OSAS) not only causes respiratory disturbances during sleep but also decreases the quality of nocturnal sleep through sleep fragmentation and sleep structure change. We aimed at comparing the changes in sleep fragmentation and structure between baseline (diagnostic) nocturnal polysomnography (NPSG) and nCPAP (nasal continuous positive airway pressure) titration trial. METHODS: One hundred and three patients with a baseline night of respiratory disturbance index (RDI) of 5 or greater and reduced RDI score during nCPAP titration night were retrospectively selected for the study. Sleep fragementation and sleep structure between baseline NPSG and the NPSG during nCPAP titration were compared. Sleep fragmentation index (SFI) was defined as the total number of awakenings and shifts to stage 1 sleep divided by the total sleep time in hour. SFI and other polysomnographic parameters were statistically compared between the two nights. RESULTS: SFI during baseline NPSG and nCPAP titration nights were 29.0+/-13.8 and 15.2+/-8.8, respectively, indicating a significant SFI decrease during nCPAP titration (t=9.7, p<0.01). SFI showed significant negative correlations with sleep efficiency (r=-0.60, p<0.01) and total sleep time (r=-0.45, p<0.01) and a positive correlation with RDI (r=0.28, p<0.01). CONCLUSION: Use of nCPAP, even during the titration, significantly decreases sleep fragmentation and improves sleep structure in OSAS patients. We suggest that SFI may be utilized as a measure of assessing OSAS severity and nCPAP efficacy.
Humans ; Polysomnography ; Retrospective Studies ; Sleep Apnea, Obstructive ; Sleep Deprivation

BACKGROUND: Many reports have shown that hormone replacement therapy(HRT) in postmenopausal women decreases lipoprotein(a)[Lp(a)]. However these had small numbers of subjects, short duration of therapy, or comparisons of only a few regimens. The influences of progesterone on Lp(a) and lipids, administered with estrogen, are controversial. METHODS: Five hundred and fifty-one postmenopausal women were divided into 4 groups : group A ; 0.625mg conjugated equine estrogen(CEE)(m=140), group B ; 0.625mg CEE plus 5mg medroxyprogesterone acetate(MPA)(m=97), group C ; 0.625mg CEE plus 10mg MPA(n=109), and group D ; 2mg estradiol valerate(E2) plus 0.5mg norgestrel(N)(n=134) and group E ; control(n=71). Lp(a) and lipids levels were measured before and 12 months after HRT. RESULTS: Estrogen replacement therapy(ERT) for 12 months lowered Lp(a) level by 37.1%. The addition of progesterone attenuated the Lp(a)-lowering effect of estrogen and decreased by 27.7%, 29.6%, and 30.3% in groups B(p<0.05), C(p<0.05), and D(p<0.0001) respectively. High density lipoprotein cholesterol(HDL-C) was increased markedly in group A(16.5%), increased moderately in groups B(10.8%) and C(11.3%), and not changed in group D. Low density lipoprotein cholesterol was decreased by 10.9%, 13.7%, 11.3%, and 17.6% in groups A, B, C, and D respectively. CONCLUSIONS: Reduction of Lp(a) with estrogen replacement therapy may be one of mechanisms for cardioprotective effect in postmenopausal women. The combined therapy of estrogen and progesterone may reveal different effects on heart due to adverse actions of progesterone on Lp(a) and HDL-C. The variations in the androgenic potency of progesterone may explaine inconsistent results on HDL-C in previous studies.
Cholesterol, LDL ; Estradiol ; Estrogen Replacement Therapy ; Estrogens ; Female ; Heart ; Hormone Replacement Therapy* ; Humans ; Lipoprotein(a)* ; Lipoproteins ; Medroxyprogesterone ; Progesterone*

INTRODUCTION: Although it is well known that medical students are not getting an adequate amount of sleep, there have been only few studies on the sleep patterns of medical students in Korea. Therefore, the present study aimed to investigate the life style and sleep patterns of Korean medical students and the impact they have on the students' academic performance. METHODS: A questionnaire package was administered to the 3rd year medical students at the Seoul National University to examine their sleep patterns on weekdays and weekends. It consisted of questions asking about their lifestyles as well as Pittsburgh sleep quality index (PSQI) and GPA (Grade Point Average) that are considered relevant to their sleep patterns. A total of 110 students (85 males and 25 females, mean age 24.4+/-20.6) responded to the survey and the result was analyzed using the independent t-test, the chi-square test, the paired t-test, Pearson's rank correlation and ANOVA. P-values of less than 0.05 were considered statistically significant in all analyses. RESULTS: The weekend bedtime was significantly delayed (01:24 on weekday; 03:12 on weekend; t=-5.23, p<0.01), the weekend rise time was delayed (07:36 on weekday; 10:30 on weekend; t=-24.48, p<0.01) and the total sleep time was increased on weekends (5:57 on weekday; 8:17 on weekend; t=15.94, p<0.01). They wished to sleep for 7 hours 6 minutes which was different from their actual weekday total sleep time (t=-11.41, p<0.01). The poor sleeper group had lower GPAs than the good sleeper group (t=2.05, p<0.05). The GPA of medical students were negatively correlated with age (r=-0.23, p<0.05), daily amount of smoking (r=-0.78, p<0.01), total amount of smoking (r=-0.75, p<0.01), weekday sleep latency (r=-0.23, p<0.05), weekend sleep latency (r=-0.23, p<0.05) and PSQI score (r=-0.30, p<0.01). CONCLUSION: Medical students were experiencing a lack of sleep during weekdays as they have a later bedtime and earlier rise time, and consequently had more hours of sleep on weekends. Overall, the responded students were experiencing poor sleep quality, and the GPAs of the poor sleeper group were lower than those of the good sleeper group.
Female ; Humans ; Korea ; Life Style ; Male ; Surveys and Questionnaires ; Smoke ; Smoking ; Students, Medical

We conducted this cohort analytic study to determine whether women with unexplained elevations of maternal serum hCG at 15-18 weeks' gestation are at increased risk for pregnancy complications and adverse perinatal outcomes. The inclusion criteria were a singleton gestation, a confirmed gestational age, and an hCG level greater than 2.0 multiples of the median (MoM). The exclusion criteria were fetal anomalies, an abnormal karyotype, molar pregnancy, and an MSAFP level greater than 2.5 multiples of the median (MoM). A group of randomly selected women with hCG levels under 2.0 MoM served as controls. Patients with elevated levels of hCG had a significantly higher risk for PIH (17.9% versus 4.5%; P <.05) and preterm delivery (17.9% versus 3.5%; P<, 05) than control. But no significant differences were observed in the incidence of intrauterine growth restriction and low birth weight and in the newborn weight. We suggested that pregnancies with unexplained elevated hCG levels should be regarded as high-risk pregnancies. And these patients require careful monitoring with adequate obstetric management.
Abnormal Karyotype ; Chorionic Gonadotropin* ; Cohort Studies ; Female ; Gestational Age ; Humans* ; Hydatidiform Mole ; Incidence ; Infant, Low Birth Weight ; Infant, Newborn ; Pregnancy ; Pregnancy Complications ; Pregnancy Outcome* ; Pregnancy* ; Pregnancy, High-Risk

OBJECTIVES: Chronic pain is one of the most common experiences of humans and a typical psychophysiological disorder. The aim of this study was to measure the psychophysiological responses in chronic pain patients using a biofeedback system, and to compare them with the results from normal healthy subjects. METHODS: Forty two patients with chronic pain (17 males and 25 females, average age 44.67+/-11.10 years) and 42 normal healthy controls (17 males and 25 females, average age 45.17+/-10.46 years) participated in this study. Electromyography (EMG), skin conductance (SC), and skin temperature (ST) were recorded using biofeedback system during the 3 phases (baseline, stress, and recovery) of stress reactivity test, and average values of them were calculated. Difference of values between two groups in each corresponding phase was analyzed with independent t-test, and change of values across phases of stress reactivity test was analyzed with paired t-test (all two-tailed, p<0.05). RESULTS: Compared to normal controls, chronic pain patients had higher value of EMG (baseline : 8.10+/-5.97 micronV vs 4.72+/-1.52 micronV, t=-3.56, p<0.01 ; stress : 11.25+/-6.89 micronV vs 8.49+/-4.78 micronV, t=-2.13, p<0.05 ; recovery : 7.12+/-3.77 micronV vs 4.78+/-1.59 micronV, t= -3.70, p<0.01) and SC (baseline : 1.06+/-1.0 micronS vs 0.42+/-0.29 micronS, t=-4.0. p<0.01 ; stress : 1.87+/-2.05 micronS vs 1.03+/-0.86 micronS, t=-2.47, p<0.05 ; recovery : 1.74+/-1.77 micronS vs 0.64+/-0.59 micronS, t=-3.8, p<0.01) in all the 3 phases. But, skin temperature comparison did not reveal significant differences in all the 3 phases between two groups. CONCLUSION: Psychophysiological responses of chronic pain patients in stress reactivity test were different from those of normal healthy controls. These results suggest that sympathetic nervous system is more activated in chronic pain patients.
Biofeedback, Psychology ; Chronic Pain ; Electromyography ; Female ; Humans ; Male ; Psychophysiologic Disorders ; Psychophysiology ; Skin ; Skin Temperature ; Sympathetic Nervous System

OBJECTIVES: OSAS (obstructive sleep apnea syndrome) is a common disorder and its consequences are often serious. It is important to detect the disorder early in the course for proper treatment. This study is to grasp the snoring clinic visitors' knowledge level of OSAS. METHODS: One hundred and seventy-nine visitors at the of snoring clinic of Seoul National University Hospital were surveyed by questionnaire about reasons of visit and knowledge of treatment methods of snoring and OSAS, diagnostic method, OSAS-related symptoms, and complications. RESULTS: Most of the respondents (89.4%) "have already heard about OSAS" and the major sources of information was the mass media (58.1%) such as television and radio. More than half (60.3%) were aware that snoring is closely related to OSAS. More than half (59.8%) recognized that a nocturnal polysomnograpy was necessary for proper diagnosis. Two thirds (67%) of the respondents noted surgery as a treatment for snoring. More than half (55.9%) answered that they would follow the doctor's advice on the treatment choice. Only 12.3% of respondents "have heard about nCPAP". No one chose nCPAP (nasal continuous positive airway pressure) as a treatment for either snoring or OSAS. About one third (34.6%) of the respondents were aware that OSAS is related to hypertension. Only 12.8% noted that OSAS is related to diabetes mellitus. CONCLUSION: Visitors at the snoring clinic were found to have substantially limited knowledge of health risks and proper treatments of OSAS. We suggest that it is crucially important to educate patients and offer easy-to-understand information on snoring and OSAS. We predict that provision of educaiton and information to patients and general public will faciliate the diagnosis and treatment of snoring and OSAS and reduce the related disorders such as hypertension, stroke, and diabetes mellitus.
Diabetes Mellitus ; Hand Strength ; Humans ; Hypertension ; Mass Media ; Surveys and Questionnaires ; Sleep Apnea Syndromes ; Sleep Apnea, Obstructive ; Snoring ; Stroke ; Television

Background and objectives: Carvedilol is a cardiovascular drug, beta- and alpha1-adrenoceptor antagonist, currently approved for the treatment of hypertension, angina, congestive heart failure by FDA. Carvedilol has been shown to attenuate oxygen free radical-initiated lipid peroxidation and to inhibit neointimal formation of aorta following vascular injury by balloon angioplasty. We have investigated the effect of carvedilol on DNA synthesis of vascular smooth muscle cells (VSMC) stimulated by platelet-derived growth factor (PDGF)-BB. MATERIALS AND METHOD: Rat aortic smooth muscle cells were obtained by the combined collagenase and elastase methods. Cells between the 4th and 8th passages were used for the experiments. Incorporated radioactivity of [3H]-thymidine was measured by liquid scintillation spectrometry. RESULTS: PDGF-BB (1 nM) increased [3H]-thymidine incorporation about 70-100% over basal value in cultured VSMC. PDGF-stimulated increase in DNA synthesis was significantly suppressed by simultaneous administration of carvedilol. In contrast, propranolol did not significantly affect 3[H]-thymidine uptake in rat aortic VSMC. CONCLUSION: The present study demonstrate that carvedilol significantly inhibits the proliferation of vascular smooth muscle cell in our condition. These results indicate that carvedilol may be effective in the treatment of cardiovascular diseases principally associated with abnormal vascular smooth muscle growth.
Angioplasty, Balloon ; Animals ; Aorta ; Cardiovascular Diseases ; Cell Proliferation ; Collagenases ; DNA ; Heart Failure ; Hypertension ; Lipid Peroxidation ; Muscle, Smooth, Vascular* ; Myocytes, Smooth Muscle ; Oxygen ; Pancreatic Elastase ; Platelet-Derived Growth Factor ; Propranolol ; Radioactivity ; Rats ; Spectrum Analysis ; Vascular System Injuries

BACKGROUND: Protamine sulfate (PS), used to neutralize the effect of heparin, is often associated with systemic hypotension. The present study was aimed to investigate the protective effects of CaCl2 on adverse hemodynamic reaction to PS. METHODS: Forty-six dogs of three groups were studied. Animals were randomly allocated to receive either; saline 10 ml (controls, n = 26), CaCl2 5 mg/kg (n = 10) or 10 mg/kg (n = 10), added to PS 3 mg/kg given intravenously 5 min after heparin (300 IU/kg, iv). Mean aortic pressure (MAP), mean pulmonary arterial pressure (MPAP), left ventricular end-diastolic pressure (LVEDP), LVdP/dtmax, and -LVdP/dtmin, and pulmonary artery (cardiac output) and left circumflex blood flow (LCX flow) were recorded up to 15 min after PS. RESULTS: PS caused significant reductions in MAP (-49%), cardiac index (CI, -66%), systemic vascular resistance index (SVRI, -22%), LVEDP (-67%), LVdP/dtmax (-36%), and LVdP/dtmin (-55%), but increased MPAP (39%) and PVRI (3.8 fold), which all increases and reductions peaked 1-3 min after PS injection in the control group. The addition of CaCl2 to PS significantly attenuated reductions of MAP (-35 and -26% in CaCl2 5 and 10 mg/kg treated dogs, respectively), CI (-34 and -37%), LVdP/dtmax (-14, -11% ), and -LVdP/dtmin (-34, -21%), and increases in PVRI (1.8 and 2.4 fold). However, both doses of CaCl2 increased MPAP (48, 82%), but not SVRI (-28, -21%) or LVEDP (-73, -75%). LCX flow increased similarly in all groups (75-137%). CaCl2 5 and 10 mg/kg iv increased plasma Ca2+ by 0.23 and 0.36 mM, respectively. CONCLUSIONS: These results suggest that the simultaneous administration of CaCl2 attenuates the adverse hemodynamic effects of PS, used to reverse heparin anticoagulation in the dog.
Animals ; Arterial Pressure ; Calcium Chloride* ; Calcium* ; Dogs* ; Hemodynamics* ; Heparin ; Hypotension ; Plasma ; Protamines* ; Pulmonary Artery ; Vascular Resistance

BACKGROUND: In Korea, cerebrovascular accident (CVA) is the most significant cause of death among older people, and the incidence of cerebral hemorrhage is much higher than that of developed countries. There have been many investigations about the risk factors for CVA in both Korea as well as developed countries. A few papers reported various risk factors for cerebral hemorrhage in developed countries:however, well-designed studies of risk factors for the various causes of CVA were rare in Korea. Therefore, the purpose of this study was to compare the risk factors for the various causes of CVA and to evaluate the risk factors compared with age- and sex-matched control groups. In addition, duplex sonographic findings of the carotid artery were evaluated in patients with cerebral infarction. METHODS: One hundred and sixty-four patients admitted to the hospital in 1996 were enrolled. The four groups were divided based on the following states: cerebral infarction (n-63), cerebral hemorrhage (n-64), cerebral infarction with atrial fibrillation (n-19), and lacunar infarction (n-18). Major risk factors were compared with age- and sex-matched control groups and among CVA groups. Duplex sonography of the carotid artery was done in 14 patients with cerebral infarction. RESULTS: In multiple logistic regression analysis, patients with cerebral infarction had higher prevalence of diabetes mellitus and lower high density lipoprotein-cholesterol level than the control group, and hypertension showed borderline significance. Patients with cerebral hemorrhage had higher prevalence of hypertension, higher high density lipoprotein-cholesterol level, and more frequent prevalence of smoking compared with the control group. Patients with cerebral infarction showed lower high density lipoprotein-cholesterol, higher low density lipoprotein-cholesterol levels, more frequent diabetes mellitus, lower prevalence of hypertension and older age than patients with cerebral hemorrhage. Patients with cerebral infarction and atrial fibrillation showed only older age than patients with cerebral infarction only. There were no differences in risk factors between patients with cerebral infarction and lacuna infarction. Atheromatous plaque was found in 71% of patients with cerebral infarction. CONCLUSION: Metabolic abnormalities played more important role in the development of cerebral infarction and hemodynamic abnormalities in cerebral infarction. Sonographic examination of the carotid artery may be useful for predicting the occurrence of cerebrovascular accident in high risk patients.
Atrial Fibrillation ; Carotid Arteries* ; Cause of Death ; Cerebral Hemorrhage ; Cerebral Infarction* ; Developed Countries ; Diabetes Mellitus ; Hemodynamics ; Humans ; Hypertension ; Incidence ; Infarction ; Korea ; Logistic Models ; Prevalence ; Risk Factors* ; Smoke ; Smoking ; Stroke ; Stroke, Lacunar ; Ultrasonography*